This story is set immediately after the conclusion of the Tokyo Mew Mew anime. Thus Ichigo and her friends are about 14 years old. Pudding is about 5 years younger. Zakuro's age is always a problem. I am told that in the manga she is only a couple of years older than Ichigo; but the anime hints that she is older than that. This story assumes that she is about 5 years older than Ichigo.
Sailor Moon and her Guardian Senshi are about a year older than Ichigo and her friends, or about 15 years old. The Sailor Moon saga must have occurred at least up through Season 3 (Sailor Moon S), because the Outer Senshi are known and are part of the story.
Prologue
Rei's eyes suddenly snapped open. Her body was drenched in sweat, her teeth hurt from grinding together, her breaths came in painful gasps, and her sweat-soaked dark hair was twisted about her face. It was still dark; the clock said 2:34 in the morning. Her body trembled. But it had been a dream.
For others, it could have been said that it was only a dream. But there was no such thing as "only a dream" to Rei; she was a magical, mystical girl, and her dreams carried portents and intimations of things that had happened, or things to come. And so the things of her dream – so vivid to her, and so horrible – were real dangers. She had to understand them.
She rose up in the bed, and placing her feet on the floor, she pushed her flowing dark hair out of her face. She made herself think, made herself remember the details. There had been terrible monsters, monsters that were only half-human because they were half beasts. And the monsters were magical and strong. They attacked Tokyo and wrought terrible destruction, and the Sailor Senshi had gone out to fight them. For Rei was one of the great Sailor Senshi – Sailor Mars.
But they had lost, and one after another they had fallen to the monsters. And finally Sailor Moon herself went out to fight them, and the horrid things had withered under her attack; but the monsters' numbers had seemed endless, and even Sailor Moon had fallen to them. And thus the dream ended, as Rei had knelt beside Sailor Moon's lifeless body, and the monsters rose up around her to kill.
Rei now rose from the bed. She knew that she would sleep no more that night, and she did not want to: she wanted no more of that dream. She made her way to the sacred fire in the shrine, and kneeling before the fire, she chanted her incantations and stared into the fire, looking for some portent of hope, or some clear vision of what the monsters were and where they came from. But in the dancing flames she could see only images of death, destruction, and hopelessness. Over and over she saw in the fire signs of the Grim Reaper, and she knew: the end was upon them. And so she sat in silence, as the minutes and hours painfully crept by. In the morning she would have to tell the others that their end was at hand.